Detachable tooth for public works machine having a particular cotter

ABSTRACT

A detachable tooth such as for an excavating bucket, which tooth is coupled to a support by engagement of a head member and a socket member and is held in the engaged condition by a cotter extending through orifices in the head and socket members, the cotter comprising a main cotter which receives an auxiliary cotter slidable relative to the main cotter in a direction parallel with the direction of engagement of the head and socket members, the auxiliary cotter being biased away from the main cotter in that direction and including a lug to keep the cotter in position in the orifices. The main cotter normally bears on one of the socket and heat members and the auxiliary cotter on the other of those members, but bears on both to protect the biasing means between the main cotter and auxiliary cotter in the event of the auxiliary cotter being driven toward the main cotter by relative closing movement of the tooth toward the support.

United States Patent [191 Moreau Rene V. Moreau. Ermenonville. France [75] Inventor:

[73] Assignee: Poclain, Le Plessis-Belleville. France [22] Filed: Oct. 5. 1973 [2]] Appl. No.: 404,126

[30] Foreign Application Priority Data Oct. 31. 1972 France 72.38539 [52] U.S. Cl 37/142 A; 85/821; 172/713 [51] Int. Cl E02f 9/28 [58] Field of Search 37/141 R. 141 T, 142 R.

1451 July 15, 1975 3.520.224 7/1970 Hensley et a1. 37/142 A 3.675.350 7 1972 Muleahy 37/142 A 3.685.178 8/1972 Ratkowski 37/142 A Primary Examiner-E. H. Eickholt Attorney. Agent. or FirmMason. Fenwick & Lawrence 157] ABSTRACT A detachable tooth such as for an excavating bucket. which tooth is coupled to a support by engagement of a head member and a socket member and is held in the engaged condition by a cotter extending through orifices in the head and socket members. the cotter comprising a main cotter which receives an auxiliary cotter slidable relative to the main cotter in a direction parallel with the direction of engagement of the head and socket members. the auxiliary cotter being biased away from the main cotter in that direction and including a lug to keep the cotter in position in the orifices. The main cotter normally bears on one of the socket and heat members and the auxiliary cotter on the other of those members. but bears on both to protect the biasing means between the main cotter and auxiliary cotter in the event of the auxiliary cotter being driven toward the main cotter by relative closing movement of the tooth toward the support.

3 Claims, 4 Drawing Figures DETACHABLE TOOTH FOR PUBLIC WORKS MACHINE HAVING A PARTICULAR COTTER ln the domaine of public works, the large number and importance of excavating machines are known. The majority of these machines has buckets or blades, the leading edges of which are provided with projecting teeth, this permitting a very substantial increase in the power of penetration into the material. Moreover, the teeth used are often detachable in order to permit their easy replacement, when wear has caused a reduction in the initial penetration characteristics. These detachable teeth are mounted on a support, on which they are generally held by means of a cotter.

The object of the invention is to provide an improved detachable tooth with a cotter of novel type.

According to the present invention there is provided detachable tooth mounted on a support, such as the leading blade of an excavating bucket in particular, in which a first of the two said elements, tooth or support, has a cavity provided with an opening, and the second of these two elements being provided with a head, which is received in the said cavity and extends into the cavity from the said opening in a direction known as the introduction direction, orifices pass through each of the two elements and are in register with each other, an organ for holding the tooth in position on its support extends into the said orifices in a direction known as the cottering direction, perpendicular to the said introduction direction, the organ comprising a main cotter having a housing which receives an auxiliary cotter, an elastic compression organ inserted between the auxiliary cotter and the main cotter and at least one lug rigidly attached to the auxiliary cotter co-operating with the head to keep the said auxiliary cotter fast to the said head in the cottering direction, this auxiliary cotter being mounted slidably in the introduction direction relative to the main cotter when in the said housing and fast with the said head in the cottering direction, the main cotter including a forward face arranged opposite a face of the orifice of the second element which includes the head, and a rear face arranged opposite a face of the orifice of the said element which includes the cavity which face is directed in the opposite direction to the said face of the orifice of the second element which includes the head, the said forward face being positioned so that it can bear against the face of the orifice of the second element including the head when the said rear face is itself bearing against the said face of the orifice of the first element including the cavity and so that it bears on the face of the orifice of the second element including the head before the elastic organ is completely crushed, and the housing with which the main cotter is provided comprising a blind cavity defined by the forward face of the said main cotter, which forward face itself comprises two sides between which the opening of the said blind cavity is arranged.

Advantageously, the lug consists of two teeth which are directed towards the said face of the orifice in the second element including the head and are separated by a distance at least equal to that separating the two faces of the said head substantially perpendicular to the said face of the orifice in the second element including the head and substantially parallel to the introduction direction.

The two faces of the head substantially parallel to the introduction direction are preferably joined to the said face of the orifice in the second element including the head by flat surfaces inclined to the introduction direction and convergent towards the centre of the orifice in this second element.

It is sometimes advantageous for the elastic organ to consist of a block of rubber adhered to the auxiliary cotter.

A better understanding of the invention will be obtained and secondary features and their advantages will become apparent, in the course of the description of the embodiment given below by way of example.

It will be understood that the description and the drawings are only given by guidance and are not limiting.

Reference will be made to the attached drawings, in which:

FIG. 1 is a section of an embodiment of detachable tooth in accordance with the invention, in a plane which is parallel to the said introduction and cottering directions and is a median plane of the main and auxiliary cotters;

FIG. 2 is a section along the line llll of FIG. 1, of the complete tooth;

FIG. 3 is a perspective view of the assembly of the organ for holding the tooth on its support; and

FIG. 4 is an elevation of a modification of the auxiliary cotter of a tooth in accordance with the invention.

A leading blade 1 of a bucket is provided with cavities 2, into which are introduced shanks 3 of special supports 4 for fitting detachable teeth 5 to blade 1. Supports 4 are fixed to blade 1 by means of rivets 6, in a manner well known in this field of technology. Each tooth 5 has a penetration point 7 and a cavity 8 provided with an opening 9. Corresponding to cavity 8, support 4 is provided with a coupling head 10, which is introduced into cavity 8 through opening 9, in a direction parallel to arrow F known as the introduction direction of this head 10 into cavity 8.

Orifices 11 are provided in detachable tooth 5 and register with an orifice 12 which passes through head 10. An organ 13 for holding tooth 5 in position on head head 10 is introduced into orifices II and 12 in a direction known as the cottering direction indicated by arrow G. Moreover, this cottering direction G is perpendicular to introduction direction F.

Holding organ 13 consists of a main cotter 14, an auxiliary cotter l5 and an elastic organ inserted between the main cotter l4 and auxiliary cotter 15, consisting in this case of a block 16 of rubber. In fact, main cotter 14 has a housing 17 into which block 16 and a portion of auxiliary cotter 15 are introduced.

Housing 17 forms a blind cavity, the opening 18 of which is defined by two sides 19 and by two ends 20 connecting sides 19. The free edges of sides 19 form the forward face of main cotter 14, the face opposite to the free edges of the said sides 19 forming the rear face 21 of the said cotter 14.

The free edges of sides 19 are arranged opposite a face 22 of the orifice 12 of the head 10, while rear face 21 of main cotter 14 is arranged opposite faces 23 of the orifices 11 in the tooth, this face 23, moreover, being opposed to face 22 of orifice 12. Moreover, the free edges of sides 19 can bear against face 22 of orifice 12, when rear face 21 of main cotter 14 is itself bearing on faces 23 of the orifices 11 in tooth 5. It will also be noted that the distance D, separating faces 19 and 22 is distinctly shorter than the distance D which separates the faces 14a and 15a of the two cotters which are in contact with rubber block 16, with only the elasticity of the rubber acting. As a result, when distance D, becomes zero when faces 19 and 22 come into mutual contact, distance D is only reduced by D, but is not zero, and this enables the crushing of block 16 to be avoided.

it will also be noted that auxiliary cotter 15 has two small teeth 24, which are directed towards face 22 of the orifice 12 of the socket and which are separated by a distance E, slightly greater than the distance E separating two flat surfaces 25 of head 10. These flat surfaces 25 form the extension of two faces 26 of head which are approximately parallel to introduction direction F, and join the said faces 26 to face 22 of the orifice 12 of the head. Flat surfaces 25 are slightly inclined to introduction direction F and converge towards the centre of orifice l2.

Lastly, it will be noted, with reference to FIGA, that in a modification rubber block 16 is adhered to face 150 of auxiliary cotter 15.

The advantages which are derived from the adoption of the detachable tooth which has been described will now be indicated.

it will firstly be noted that main cotter 14 is formed as an element rendered very strong by the presence of sides 19 and ends 20. The corresponding particular structure is substantially nondeformable, at least when it is subjected only to those strains which are likely to be applied to it in use.

Furthermore, the structure which has just been recalled has permitted formation of a blind cavity in main cotter 14: housing 17. Rubber block 16 is entirely contained in the said housing 17 and is consequently very well protected from the direct reach of foreign bodies (earth, stones, etc.), which happens very frequently on sites where machines provided with detachable teeth 5 move about.

Of course, it will have been appreciated that, taking into account their inclination, flat surfaces 25 facilitate introduction of the assembly of the two cotters l4 and 15 and of the block of rubber 16 into orifices 11 and 12.

Furthermore, the actual structure of the two cotters is simple and inexpensive.

In order to improve the conditions of use of such cotters, it is sometimes advantageous to fix the block of rubber 16 to face 150 of auxiliary cotter 15. In particular, this procedure avoids the risk of mislaying block 16 and in fact reduces the number of separate elements to two: the auxiliary cotter l5 block 16 on the one hand, and the main cotter 14 on the other.

It will also be mentioned that the actual arrangement of rubber block 16 inside housing 17 enables any tearing of the said block upon location and removal of the complete cotter to be avoided. The said block 16 is therefore not deteriorated at all during the above mentioned operations, as opposed to what happens with the previously known cotters, in which the block of rubber projects from the main body of these cotters.

Moreover, it will be appreciated that, if the elastic organ which has been selected in the illustrated example consists of a block of rubber, it may be advantageous in certain applications, particularly to carry out work at very high temperatures at which carbonization of rubber is experienced, to select a metal spring, for example a leaf-spring, instead and in place of the rubber block 16 shown.

The invention is not limited to the embodiments de scribed above but, on the contrary, covers all the modifications which could be made to them without departing from their scope or spirit.

I claim:

1. An improved detachable tooth mounted on a support, such as the leading blade of an excavating bucket in which a first of the two elements, either the tooth or the support, has a cavity with an opening, the second of the two elements has a head insertable into the cavity from the opening in an introduction direction, orifices extend through each of the two elements in register with each other, a main cotter extends into said orifices in a cottering direction perpendicular to the introduction direction, for retaining the tooth on the support and for retaining an auxiliary cotter with at least one lug cooperating with the head to prevent movement in the cottering direction of the auxiliary cotter relative to the head and which receives an elastic compression member inserted between the auxiliary cotter and the main cotter wherein the auxiliary cotter is mounted slidably in the introduction direction relative to the main cotter, said improvement comprising side walls, end walls and a bottom wall on the main cotter adjacent the auxiliary cotter to form a blind cavity wherein the elastic compression member is inserted behind the auxiliary cotter to bias the auxiliary cotter outwardly into engagement with the head and wherein the side walls increase the strength of the main cotter, protect the compression member from the environment, and prevent said elements from crushing the elastic compression member.

2. The improved detachable tooth in accordance with claim 1 wherein the lug on the auxiliary cotter comprises two projections which are directed outwardly from the main cotter when the auxiliary cotter is positioned in the blind cavity and are separated by a distance at least equal to the length of the orifice in the head.

3. The improved detachable tooth claim 1 wherein the elastic compression member comprises a block of rubber adhered to the auxiliary cotter. 

1. An improved detachable tooth mounted on a support, such as the leading blade of an excavating bucket in which a first of the two elements, either the tooth or the support, has a cavity with an opening, the second of the two elements has a head insertable into the cavity from the opening in an introduction direction, orifices extend through each of the two elements in register with each other, a main cotter extends into said orifices in a cottering direction perpendicular to the introduction direction, for retaining the tooth on the support and for retaining an auxiliary cotter with at least one lug cooperating with the head to prevent movement in the cottering direction of the auxiliary cotter relative to the head and which receives an elastic compression member inserted between the auxiliary cotter and the main cotter wherein the auxiliary cotter is mounted slidably in the introduction direction relative to the main cotter, said improvement comprising side walls, end walls and a bottom wall on the main cotter adjacent the auxiliary cotter to form a blind cavity wherein the elastic compression member is inserted behind the auxiliary cotter to bias the auxiliary cotter outwardly into engagement with the head and wherein the side walls increase the strength of the main cotter, protect the compression member from the environment, and prevent said elements from crushing the elastic compression member.
 2. The improved detachable tooth in accordance with claim 1 wherein the lug on the auxiliary cotter comprises two projections which are directed outwardly from the main cotter when the auxiliary cotter is positioned in the blind cavity and are separated by a distance at least equal to the length of the orifice in the head.
 3. The improved detachable tooth claim 1 wherein the elastic compression member comprises a block of rubber adhered to the auxiliary cotter. 